Mixed Licensing Strategy
Learn how to optimize M365 licensing costs by mixing plan tiers, using group-based assignment, identifying waste, and calculating the breakeven point between add-on stacking and tier upgrades. Includes real-world budget examples for 50, 200, and 1,000-user organizations.
Key Facts
- You can mix any M365 plan tiers within a single tenant — not every user needs the same license.
- The average organization wastes 15-25% of its Microsoft 365 license spend on unused or underutilized licenses.
- Group-based licensing in Entra ID (requires Entra ID P1 or P2, included in M365 E3+) lets you auto-assign licenses based on security group membership.
- License reassignment has a 90-day rule: you can reassign a license to a different user only after 90 days (or if the original user is deleted).
- The breakeven point for E3 + add-ons vs E5 is typically around 3-4 add-ons — once you are stacking more than $20/user/month in add-ons on E3, upgrading to E5 usually saves money.
- Microsoft 365 Admin Center > Billing > Licenses shows license utilization — users with licenses but no sign-in activity in 30/60/90 days are candidates for reclamation.
- Frontline worker licenses (F1 at $2.25/user/month, F3 at $8/user/month) are dramatically cheaper than knowledge worker licenses and perfectly sufficient for shift workers, retail staff, and factory floor employees.
The Golden Rule: Not Everyone Needs the Same Plan
The single biggest licensing mistake organizations make is putting every user on the same plan. A receptionist does not need Defender for Endpoint P2 or eDiscovery Premium. A warehouse worker does not need desktop Office apps. A CEO absolutely needs advanced identity protection. The best time to implement mixed licensing is during your initial Microsoft 365 rollout — assign the right license tier from the start rather than migrating everyone to E5 and downgrading later.
Microsoft explicitly supports mixed licensing within a single tenant. You can have E5 users, E3 users, F3 users, and Business Premium users all in the same Microsoft 365 environment. The only requirement: every user who accesses M365 services must have an appropriate license assigned. This is particularly relevant during tenant-to-tenant migrations after a merger — the acquiring company's license mix often looks very different from the acquired company's, and both need to coexist in the target tenant.
Common Mixed Licensing Scenarios
Typical 200-Person Organization
Group-Based License Assignment
Once you have defined your user tiers, use Entra ID group-based licensing to automate assignment:
- Create security groups: "M365-E5-Users", "M365-E3-Users", "M365-F3-Users"
- Assign license plans to each group in Entra ID → Licenses
- When a user is added to a group, they automatically get the correct license
- When they are removed, the license is automatically reclaimed
- Requires Entra ID P1 (included in E3/E5/Business Premium)
- Handles conflicts: if a user is in multiple groups, the highest-tier license takes precedence
Pro Tip
Combine group-based licensing with dynamic groups. For example, create a dynamic group rule: "department equals Sales AND jobTitle contains Manager" → automatically gets E5. This eliminates manual license assignment entirely.
The Breakeven Calculation: When E5 Beats E3 + Add-Ons
For each user segment, calculate the real cost of E3 plus the add-ons they need:
- E3 ($36) + just Entra ID P2 ($9) = $45. Still cheaper than E5 ($57) by $12.
- E3 ($36) + Entra ID P2 ($9) + Defender Endpoint P2 ($5.20) = $50.20. Still $6.80 cheaper.
- E3 ($36) + Entra ID P2 ($9) + Defender Endpoint P2 ($5.20) + Audio Conferencing ($4) = $54.20. Only $2.80 cheaper, but missing a LOT of E5 features.
- The moment you need 3+ security add-ons on E3, E5 almost certainly wins on total value.
- Key test: If a user needs any E5-exclusive compliance feature (Insider Risk, eDiscovery Premium, Information Barriers), E5 is the only option.
License Reassignment Rules
Microsoft has a 90-day reassignment restriction: once you assign a license to a user, you cannot reassign that same license to a different user for 90 days. This prevents license "hot-swapping."
- The 90-day rule applies to the license SKU, not the user. If a user leaves, you can reclaim and reassign.
- Exception: devices. Device-based licenses (Windows 365, Teams Rooms) follow the device, not the user.
- Plan for 5-10% license buffer above your headcount for onboarding, temporary workers, and flexibility.
Did You Know?
You can mix any M365 plan tiers within a single tenant — not every user needs the same license.
Test Your Knowledge
Question 1 of 3
A 200-user company currently has all employees on Microsoft 365 E3. An audit reveals that 60 users are retail store employees who only use Teams on shared tablets and never open desktop Office apps. What is the most cost-effective action?
Chapter Summary
- 1The most expensive licensing mistake is giving everyone the same plan. A mixed approach (E5 for executives, E3 for knowledge workers, F3/F1 for frontline) can save 30-40% with no loss of functionality.
- 2Group-based licensing in Entra ID (requires P1, included in E3+) automates license assignment via security groups. Dynamic groups can auto-assign based on department, job title, or other user attributes.
- 3A 500-user org putting everyone on E3 spends $18,000/month. A mixed approach (50 E5, 250 E3, 200 F3) costs $12,250/month — a 32% savings.
- 4The E3-to-E5 breakeven point is around 3-4 add-ons. If you are paying E3 ($36) plus $20+ in add-ons (Teams Phone, Audio Conferencing, Defender P2, Entra ID P2), upgrading to E5 at $57 is cheaper and simpler.
- 5Audit license waste quarterly: check the M365 Admin Center for assigned-but-unused licenses, users with no sign-in for 60+ days, and users with E3 licenses who only use web apps (candidates for F3 downgrade).
- 6License reassignment follows a 90-day rule — you can move a license to a different user after 90 days or immediately if the original account is deleted. Annual commitments cannot reduce seat count mid-term.
- 7Real-world budget examples show a 1,000-user enterprise saving $253,500/year with mixed licensing versus all-E5, even after adding Copilot, Teams Phone, and Teams Rooms Pro for select users.
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